California Quail Callipepla californica
This species can be found in captivity and escapes are rarely encountered in the wild, such as the first bird shown below. In some parts of Europe these have become naturalised and feral populations breed in the wild at several locations. Those in Corsica are regarded as self-sustaining and therefore 'countable' but I was unable to locate any here during a recent visit.
California Quail, Yaqui Well (California, USA), 22nd April 2005